Double-Switch术治疗矫正型大动脉转位

目的 使矫正型大动脉转位 (CTGA)不仅从生理上 ,而且从解剖上得到纠正。 方法 资料为美国波士顿儿童医院心脏外科收治的 9例 CTGA患者 ,年龄 2～ 16个月 ,体重 3.1～ 11kg。术前均行彩色多普勒超声心动图和心导管造影检查 ,心排血量和心功能测定。 9例患者均施行了 Double- Switch术 ,合并的其它畸形都予以纠治。 结果9例患者均存活 ,术后彩色多普勒超声心动图示左、右心功能明显改善。 结论 小婴儿 CTGA应尽可能早期选做Double- Switch术 。

纠正型大动脉转位double switch术后超声心动图随访

目的:评估双调转术(double switch operation)治疗纠正型大动脉转位(corrected transposition of the great ar-tery,CTGA)的手术效果。方法:35例CTGA行Double switch术,其中Senning+ASO(大动脉调转术)20例,Senning+Rastelli术15例。采用回顾性研究的方法,术后1次或多次行超声心动图随访,平均随访(16.8±20.9)月,最长术后8年,最短术后1月。结果:术后右室心肌工作指数较术前明显下降,术后三尖瓣反流减轻。术后总的肺静脉梗阻发生率5.7%,腔静脉梗阻发生率2.8%,左心流出道梗阻发生率11.4%,右心流出道梗阻发生率11.4%,残余分流发生率17.1%。Senning+Rastelli组左室流出道梗阻发生率较高。结论:Double switch术可改善右室功能,减轻三尖瓣反流,术后残余分流及梗阻发生率较低,是治疗CTGA的理想手术方法。

Design and Comparison of Electrically Excited Double Rotor Flux Switching Motor Drive Systems for Automotive Applications

This paper presents a cost-effective driving system for automotive applications based on a double rotor electrically excited flux switching machine(FSM).Benefiting from a double rotor topology,this FSM can realize a drum winding design and thus winding ends are effectively shorten and the copper loss is mitigated.The machine structure,operation principle and design consideration are studied and further verified by time-stepping finite element method.Moreover,three topologies of drive circuit for the proposed FSM are introduced.By using electromagnetic-circuit coupling simulation,a comparison between three different three drive systems are performed,with focus on the system cost and overall electromagnetic performance,especially the effect of current control and torque ripple.A prototype is established and tested.Relevant experimental results verify the effectiveness of the proposed new FSM drive system.

Performance of Double-Pole Four-Throw Double-Gate RF CMOS Switch in 45-nm Technology

In this paper, we have investigated the design parameters of RF CMOS switch, which will be used for the wireless tele-communication systems. A double-pole four-throw double-gate radio-frequency complementary-metal-oxide-semicon- ductor (DP4T DG RF CMOS) switch for operating at the 1 GHz is implemented with 45-nm CMOS process technology. This proposed RF switch is capable to select the data streams from the two antennas for both the transmitting and receiving processes. For the development of this DP4T DG RF CMOS switch we have explored the basic concept of the proposed switch circuit elements required for the radio frequency systems such as drain current, threshold voltage, resonant frequency, return loss, transmission loss, VSWR, resistances, capacitances, and switching speed.

Capacitive Model and S-Parameters of Double-Pole Four-Throw Double-Gate RF CMOS Switch

In this paper, we have analyzed the Double-Pole Four-Throw Double-Gate Radio-Frequency Complementary Metal-Oxide-Semiconductor (DP4T DG RF CMOS) switch using S-parameters for 1 GHz to 60 GHz of frequency range. DP4T DG RF CMOS switch for operation at high frequency is also analyzed with its capacitive model. The re-sults for the development of this proposed switch include the basics of the circuit elements in terms of capacitance, re-sistance, impedance, admittance, series equivalent and parallel equivalent of this network at different frequencies which are present in this switch whatever they are ON or OFF.

A General Method in the Synthesis of Ternary Double Pass-Transistor Circuits

A general method for designing ternary circuits using double pass-transistor logic is investigated. The logical relation of each MOS transistor is formulated by using the transmission operation in order to make effective and practical use of the circuits. A way to generate ternary complementary and dual circuits by applying the complementarity and duality principles is presented. This new static ternary double pass-transistor logic scheme has some favorable properties：the use of standard CMOS process without any modification of the thresholds, a perfectly symmetrical structure,a full logic swing, the maximum possible noise margins, a less complex structure, and no static power consumption. HSPICE simulations using TSMC 0.25μm CMOS technology and a 3V power supply demonstrate the effectiveness of the proposed design.

Controllable double electromagnetically induced transparency in a closed four-level-loop cavity-atom system

We present a theoretical study of an optical cavity coupled with single four-level atoms in closed loop formed via applied control lasers. The transmitted probe field from the cavity is analyzed. We show that the electromagnetically induced transparency（EIT） in the cavity and the normal mode splitting will be very different with changing the closed interaction phase and the intensity of the free-space control laser. This coupled cavity-atom system presents a variational double-EIT that comes from modulating the splitting of the dark state, which means that we could realize the gradual transfer between one EIT peak and two EIT peaks by adjusting the applied control lasers, and the normal mode splitting sidebands will shift slightly by changing the free-space control laser. This means that we could control the output cavity probe field more freely and it is easer to realize optical switch controlled by more parameters. We also depict the angular dispersion of the intracavity probe field in different free-space control laser. The large phase shift（-π → π） of the reflected intracavity probe field will be very useful for optical temporal differentiation and quantum phase gate.

Photon-photon interactions with inner coupled double-cavity

This paper describes the interaction between two spatial modes of the optical fields with a single atom trapped inner coupled double-cavity. Theoretical derivation and numerical simulation with the experimental available parameters show that photon-photon switching and π phase shift of single photons may be achieved with current experimental technology. As the probe and control fields are in different spatial modes, the system is superior for implementing cavity QED-based photonic quantum networks.

Modeling and Analysis of Submerged Arc Weld Power Supply Based on Double Closed-Loop Control

According to the soft-switching pulsed SAW (Submerged arc weld) weld power supply based on the double closed-loop constant current control mode, a small signal mathematic model of main circuit of soft-switching SAW inverter was established by applying the method of three-terminal switching device modeling method, and the math-ematic model of double closed-loop phase-shift control system circuit was established by applying the method of state-space averaging method. Dynamic performance of the inverter was analyzed on base of the established math-ematic model, and the tested wave of dynamic performance was shown by experimentation. Research and experimentation show that relation between structure of the power source circuit and dynamic performance of the controlling system can be announced by the established mathematic model, which provides development of power supply and optimized design of controlling parameter with theoretical guidance.

Lead-free hybrid two-dimensional double perovskite with switchable dielectric phase transition

Molecular dielectric switches constitute a type of intelligent materials that are highly coveted for their distinctive advantages of switchable dielectric responses,lightweight,and mechanical flexibility.Twodimensional(2D)hybrid perovskites have demonstrated excellent promise for assembling dielectric switches,in which the dynamic motions of organic moieties afford driving force to trigger switchable dielectric phase transition.Here,we successfully assembled a new lead-free hybrid double perovskite,(CHA)4Cu Bi Br8(1,CHA=cyclohexylammonium),adopting a typical 2D structural motif,which shows dielectric anisotropy and bistable behaviors during the reversible phase transition near T_(c)=378 K(the Curie temperature).That is,its dielectric constants could be switched and tuned between high-dielectric and low-dielectric states.Structure analyses reveal that the ordered-disordered transformation of the organic CHA+moiety and distortion of inorganic framework account for its phase transition.This result will stimulate further exploration of molecular dielectric switches in this 2D environmentally friendly family.

Diode end-pumped self-Q-switched and mode-locked Nd,Cr：YAG /KTP green laser

We first experimentally demonstrate a laser-diode end-pumped self-Q-switched and mode-locked Nd,Cr：YAG green laser with a KTP crystal as the intra-cavity frequency doubler. The device produces an average output power of 680 mW at 532 nm. The corresponding pulse width of the Q-switched envelope of the green laser is 170 ＋ 20 ns. The mode-locked pulses have a repetition rate of approximately 183 MHz and the average pulse duration is estimated to be around sub-nanosecond. It is found that the intra-cavity frequency doubling greatly improves the modulation depth and stability of the mode-locked pulses within the Q-switched envelope.

Double Switch术治疗先天性矫正性大动脉转位二例

目的 介绍解剖矫治先天性矫正性大动脉转位的手术特点。 方法 2例矫正性大动脉转位患者 ,1例 9个月 ,合并室间隔缺损、肺动脉高压 ,行Senning加动脉调转术 ;1例 2 3岁 ,合并室间隔缺损、肺动脉狭窄、三尖瓣关闭不全 ,行Rastelli加Senning术。 结果 2例患者全部成活 ,其中 1例术前出现Ⅲ度房室传导阻滞 ,安装永久起搏器 ,术后超声检查心室功能正常 ,心内隧道和心外管道通畅。无三尖瓣反流。

基于DPA-Switch C/DC变换器的设计

开关电源以其高效率、低功耗等特点在各领域应用广泛。作为开关电源主要组成部分的DC/DC变换器,具有高精度,强隔离性和高稳定性等特点,是具有特殊功能的混合集成电路。DPASwitch系列产品是PI公司生产的高度集成DC/DC开关转换IC,其性能优越、设计灵活。简单介绍了DPA-Switch系列芯片的原理与主要功能,给出了三种基于该系列芯片DC/DC变换器的设计实例:单端反激式单路输出电路、单端正激式单路输出电路和单端反激式双路输出电路,包括电路原理图和测试所得的电性能指标,并对其工作原理进行了说明。

双调转术(Double-Switch手术)的临床应用

目的 探讨Double Switch手术方法的临床应用。方法 采用Double Switch手术方法纠治房室连接和心室大动脉连接不一致的复杂先天性心脏病病儿 3例 ,其中 1例为纠正型大血管错位、室间隔缺损、肺动脉狭窄伴轻度三尖瓣反流 ,2例为房室连接不一致、右心室双出口、肺动脉狭窄、室间隔缺损、三尖瓣轻 -中度反流。心房内采用Senning术 ,心室内采用Rastelli术的方法 ,从解剖上彻底予以纠治。结果 手术均取得成功 ,恢复顺利 ,分别术后 11d、18d和 2 1d出院。术后随访心电图窦性节律 ,超声检查示心功能正常 ,腔静脉、肺静脉血流通畅 ,同种带瓣管道和心内隧道血流无梗阻。结论 对房室连接和心室大动脉连接不一致病例 ,特别是解剖右心室功能不全和三尖瓣反流者 ,应首选Double Switch手术。

基于双模式变频移相调制的单级式双有源桥型DC-AC变换器

针对单级式双有源桥(DAB)型DC-AC变换器关断电流较大和软开关范围有限的问题,该文提出一种双模式变频移相调制策略。首先,对DAB变换器的单移相(SPS)调制和扩展移相(EPS)调制进行时域分析,得到其功率传输特性;然后,分析变换器的关断电流与软开关条件,得到移相比和开关频率约束方程;在此基础上,分析双模式间的移相比边界条件,提出变换器运行模式的切换机制,从而在实现变换器单级功率变换的同时,保证全范围软开关并降低低压侧的关断电流;最后,通过仿真和实验验证了所提调制策略的有效性与可行性。

超声心动图在矫正型大动脉转位患儿二期双调转术中的应用价值

目的 探讨超声心动图在矫正型大动脉转位(CTGA)患儿二期双调转术(DS)中的应用价值。方法 选取于外科行二期DS的17例CTGA患儿,分析超声心动图对其肺动脉环扎(PAB)术前诊断情况,比较PAB术前、后左心室形态及血流动力学情况;应用超声心动图观察DS术前、后左心室血流动力学变化。结果 17例CTGA患儿,PAB术前超声心动图准确诊断15例(88.24%);误诊2例(11.76%),均误诊为房室连接不一致型右心室双出口。PAB术后肺动脉内径、三尖瓣反流束宽均缩小,左心室舒张末期内径、左心室收缩末期内径、左心室后壁舒张末期厚度、室间隔舒张期厚度、左心室质量及肺动脉血流速度均明显增大,反流程度减轻,与PAB术前比较差异均有统计学意义(均P<0.05)。DS术后左心室心肌做功指数(MPI)明显增大,右心室MPI、左心室射血分数均明显减低,与DS术前比较差异均有统计学意义(均P<0.05);6例合并心功能不全(3例死亡,3例随访中)患儿中,室间隔完整3例,合并室间隔缺损3例(缺损直径分别为0.13 cm、0.15 cm、0.18 cm);11例心功能正常患儿室间隔缺损直径平均(0.37±0.18)cm。结论 超声心动图可准确诊断CTGA,CTGA患儿PAB术后左心室质量明显提高,可行DS;DS术后近期易合并心功能不全及主动脉瓣反流。

High Frequency Charging Techniques—Grid Connected Power Generation Using Switched Reluctance Generator

Power generation becomes the need of developed, developing and under developed countries to meet their increasing power requirements. When affordability increases their requirement of power increases, this happens when increased per capita consumption. The existing power scenario states that highest power is produced using firing of coals called thermal energy. A high efficiency Switched Reluctance Generator (SRG) based high frequency switching scheme to enhance the output for grid connectivity is designed, fabricated and evaluated. This proposed method generates the output for the low wind speed. It provides output at low speed because of multi-level DC-DC converter and storage system. It is an efficient solution for low wind power generation. The real time readings and results are discussed.

混合级联十一电平逆变器功率与开关损耗双均衡倍频调制方法

混合级联多电平逆变器可以利用较少的开关器件实现较高电平输出,进而得到了广泛应用;但实现高低压单元间功率均衡难度更大。直流侧采用电池组模块进行供电时,功率达不到均衡会使得各H桥单元对应的电池组模块处于不同的放电特性,增大了故障概率和维修难度且增加了后期的维修成本。针对此问题,提出2种1:1:1:2混合级联十一电平逆变器功率和开关损耗双均衡倍频调制方法。首先,2种方法分别对3个低压单元采用三角载波、重构载波进行移相,从而实现在全调制度范围内将逆变器的等效开关频率由fc提高至6fc/12fc;使得低压单元各开关器件开关次数均围绕在60次/174次左右上下浮动,实现了低压单元内开关损耗均衡;使得调制度M=0.9/0.6/0.3时低压单元输出功率均围绕在657.5 W/293.5 W/73.5 W上下浮动,实现低压单元间的功率均衡,其次对高压单元采用阶梯波低频调制,随调制度的变化对导通角进行动态调整,使得高压单元各开关器件开关次数均为1次,实现了高低压单元内开关损耗均衡;使得调制度M=0.9/0.6/0.3时高压单元与低压单元输出功率均围绕在1317 W/657.5 W、586 W/293.5 W、146.5 W/73.5 W上下浮动,实现了高低压单元间功率均衡,之后对比分析2种方法各自的优缺点及其适用场合。最后,通过实验验证该方法的正确性和可行性,并给出了直流电压比为1:1:1:...:x的混合级联H桥逆变器双均衡的普适方法。

面向HVDC应用的逆阻型IGCT关断特性研究

为研究逆阻集成门极换流晶闸管(RB-IGCT)的电流关断特性,指导RB-IGCT换流阀设计,此处搭建了RB-IGCT的电流关断测试电路,对其电流关断特性进行了实测,并采用双指数函数对电流关断特性进行数学拟合。最后基于拟合到的关断电流数学模型,在PSCAD/EMTDC中搭建了IGCT电流关断的器件级功能模型进行仿真测试,仿真和试验结果的一致性表明基于双指数函数的IGCT电流关断模型的准确性,为后续工程应用时IGCT关断电压应力研究以及RB-IGCT阀均压设计提供了快速有效的仿真手段。